1. Field of the Invention
The invention relates to a light-emitting element and, in more particular, to a high-intensity light-emitting element.
2. Related Art
A conventional light-emitting element is known in which an n-type GaAs buffer layer, an n-type light reflection layer portion composed of a combination of a (AlXGa1-X)YIn1-YP layer (0≦X≦1, 0.4≦Y≦0.6) and a AlXGa1-XAs layer (0≦X≦1), an n-type AlGaInP cladding layer, an undoped AlGaInP active layer, a p-type AlGaInP cladding layer, a p-type GaInP intermediate layer and a p-type GaP current dispersion layer are formed on an n-type GaAs substrate in this order, and the p-type AlGaInP layer has a dopant suppression layer at a portion not in contact with an undoped AlGaInP layer and the p-type GaInP intermediate layer (e.g., see JP-A 2007-42751).
In the light-emitting element described in JP-A 2007-42751, it is possible to improve reliability of relative output and reverse voltage by including the above-mentioned configuration while realizing high intensity.
However, in the light-emitting element described in JP-A2007-42751, when light emitted from the undoped AlGaInP active layer reaches the GaAs substrate, the GaAs substrate is excited by the light and the light equivalent to a bandgap of the GaAs may be radiated from the GaAs substrate to outside of the light-emitting element.